中国激光, 2010, 37 (4): 1132, 网络出版: 2010-04-20
连续脉冲双激光束焊接钢铝合金
CW/PW Dual-Beam YAG Laser Welding of Steel/Aluminum Alloy Sheets
激光技术 双激光束焊接 钢铝合金 剪切强度 laser technique dual-beam laser welding steel/aluminum alloy shearing strength
摘要
随着汽车轻量化越来越得到重视,钢铝合金异种金属焊接结构成为研究的重点。采用YAG连续(CW)和脉冲(PW)两种激光设备,对连续脉冲双激光束复合热源焊接工艺进行了研究,并借助扫描电镜(SEM)、电子探针微区分析(EPMA)、显微硬度计、拉伸实验机等设备对焊缝进行了分析与测试。实验结果表明,连续激光匹配适当的脉冲激光进行双激光焊接,可以有效地减少或避免气孔的产生,同时可以使用低功率的连续激光实现较深的焊接,扩大低功率激光设备使用范围。 双激光束焊接过程中,由于脉冲激光的作用,焊缝中的Fe穿入Al中,在焊缝底部Fe-Al交界处形成了钩状的不规则结构,这种结构的产生可以增强Fe,Al两种材料的连接强度。在焊缝底部Fe-Al交界处形成了高硬度、高脆性的Fe-Al金属间化合物。钢铝合金双激光搭接焊焊缝剪切强度为128 MPa,剪切断裂断口呈现为准解理型断裂形貌。
Abstract
The development of a new welding method for dissimilar metals is strongly required for weight reduction of automobiles. The most popular and important combination of dissimilar metals is steel and aluminum. The lap joining of steel/aluminum alloy is carried out using the continuous wave-pulse wave (CW-PW) dual-beam YAG laser welding method. The tests are also performed for the lap joints using scanning electron microscopy (SEM),electron probe microzone analysis (EPMA),micro-hardness tester,tensile testing machine. The results show that the CW laser matching the appropriate PW laser for dual-beam laser welding can effectively reduce or avoid the produce of pores,as well as the deeper penetration can be obtained using the low-power CW laser,which expands the scope of the low-power CW laser equipments. In the dual-laser beam welding process,the Fe penetrates into the Al due to the role of pulsed laser. And the irregular hook-like structure produced in the bottom of welding seam,which can enhance the Fe/Al joint strength. A brittle Fe-Al intermetallic compound (IMC) layer formed at the join interface. The shearing strength of the lap joint is 128 MPa,and the morphology is quasi-cleavage fracture.
石岩, 张宏, 渡部武弘, 唐敬国. 连续脉冲双激光束焊接钢铝合金[J]. 中国激光, 2010, 37(4): 1132. Shi Yan, Zhang Hong, Takehiro Watanabe, Tang Jingguo. CW/PW Dual-Beam YAG Laser Welding of Steel/Aluminum Alloy Sheets[J]. Chinese Journal of Lasers, 2010, 37(4): 1132.